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Title: Revealing electronic state-switching at conical intersections in alkyl iodides by ultrafast XUV transient absorption spectroscopy
Abstract

Conical intersections between electronic states often dictate the chemistry of photoexcited molecules. Recently developed sources of ultrashort extreme ultraviolet (XUV) pulses tuned to element-specific transitions in molecules allow for the unambiguous detection of electronic state-switching at a conical intersection. Here, the fragmentation of photoexcitediso-propyl iodide andtert-butyl iodide molecules (i-C3H7I andt-C4H9I) through a conical intersection between3Q0/1Q1spin–orbit states is revealed by ultrafast XUV transient absorption measuring iodine 4dcore-to-valence transitions. The electronic state-sensitivity of the technique allows for a complete mapping of molecular dissociation from photoexcitation to photoproducts. In both molecules, the sub-100 fs transfer of a photoexcited wave packet from the3Q0state into the1Q1state at the conical intersection is captured. The results show how differences in the electronic state-switching of the wave packet ini-C3H7I andt-C4H9I directly lead to differences in the photoproduct branching ratio of the two systems.

 
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Award ID(s):
1660417
NSF-PAR ID:
10183255
Author(s) / Creator(s):
; ; ; ; ; ; ; ;
Publisher / Repository:
Nature Publishing Group
Date Published:
Journal Name:
Nature Communications
Volume:
11
Issue:
1
ISSN:
2041-1723
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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